Stray Cat Strut [Stubbing Never - lol] - Chapter Twenty - Nanomachines, Son

In a contaminated world on the brink of collapsing under countless dungeons, a harsh place where if you were unable to summon a creature, it meant you could die at any moment. Alas, the chance of summoning was very low for anyone—except nobles.On a fateful day, an unemployed guy from earth was reincarnated as a nameless slave and had contracted an illness—mana circulation disorder—that would prevent him from living past 30.His only chance was to summon something decent. Luckily for him, a second chance appeared… A challenge from the gods… By getting through it, he finally gained what he wanted.A sword demon....one of demon kings.[Do you want to evolve your summon?][Your summon has two paths to evolve]–[Hellfire Demon]–[Wind Demon][Do you want to use 2,000 Chaos Points to unlock another evolution path?]–[Supreme Sword Demon][Description]: A slave demon… An ancient demon… An extinct demon… They possess swordsmanship unparalleled in all of hell; no demon can defeat them. However, what all demons in hell fear is their ability—even demon gods are afraid of them. Each time they kill someone with their sword, the victim's existence is obliterated from the world. No one can remember them after they're dead.However, that was just the beginning of a Godslayer’s fate when he figured out the reincarnators. And unluckily, the world should have existed only one reincarnator. He had to kill them to survive, or they would kill him.[Author’s Note]*Is the MC a slave? Yes, he is, but it’s just a leftover label from his old identity in this world. The moment Alaric, a fourth-year university student, reincarnated into that slave body, I don’t think he should even be considered a slave anymore. Moreover, he gets rid of his inferior identity once he clears the final challenge of the Nameless God in Chapter 18.*Is the MC OP? Not exactly, since his early power isn’t really a cheat. The real cheat everyone expects only shows up after Chapter 19.

The tale of Oliver.
An orphan boy from a Mine, in 19th century Europe, filled with Magic.

Having lived a normal life all his life and died without being able to fulfill his desire and when he’s given a task by a god, watch how he takes the protagonists girls while making it hard for the hero.

Reborn and returning, he possesses medical skills, can practice immortality, has a slave who is the king of killers, and a maid who is the school beauty pursued by everyone. Even casually taking out a piece of trash can shock the world. His return has set this world ablaze.